Keywords do not need to be repeated verbatim throughout a piece of content. In a headline, in particular, you want to use a keyword (or keywords) in a way that makes the most sense to your audience. The goal should be to write a stellar headline (somewhere between 4-9 words) that clearly explains what a piece of content is about.
Nothing is more of a buzzkill than having a headline that’s awkwardly framed around one keyword phrase or, worse, that forcibly repeats a keyword phrase. This rule applies not only to headlines, but also the content on the page: the goal should be to inform the reader, not to inform the search engines.